Question 1

Which of the following best describes the difference between a sample and a population in statistics?

Accepted Answer

A sample is a subset of the population, selected to represent the population, while a population includes all members of the group being studied.

Question 2

A researcher wants to estimate the average weight of adult males in a country. Which of the following is the best reason for using a sample rather than a census?

Accepted Answer

A sample is preferred because the population contains a large number of individuals, and it is not easy to obtain their weights.

Question 3

A pollster conducts a survey about how American adults pay their bills. She gives her survey to 45 other residents in her apartment building. Which of the following best identifies the sample?

Accepted Answer

The 45 people in her apartment building who completed her survey

Question 4

A company is interested in determining whether a pesticide is safe for general use. Genetically engineered test plants are placed in the environment. Which of the following best describes the possibility of bias in this study?

Accepted Answer

There is a possibility of bias, because the test plants may not react to the pesticide in the same way as natural plants.

Question 5

A marketing expert is planning a survey in which 400 people will be randomly selected from each age group: 15-19, 20-29, and so on. What type of sampling is used?

Accepted Answer

Stratified sampling

Question 6

Which of the following is an example of a voluntary response sample?

Accepted Answer

Post a survey question on the Internet and ask readers to respond to that question.

Question 7

A study of 1,000 randomly selected adult Americans found that 89% said they had car insurance. Identify the sample and the population.

Accepted Answer

Sample: 1,000 randomly selected adult Americans; Population: All adult Americans

Question 8

Which of the following best describes a stratified sampling method?

Accepted Answer

The population is divided into groups, and a random sample is taken from each group.

Question 9

A magazine chooses its 'favorite' columnist by sampling responses from readers who choose to send in ballots printed in the magazine. What type of sample is this?

Accepted Answer

Voluntary response sample

Question 10

Which of the following is the best method for conducting a meaningful statistical study?

Accepted Answer

Randomly select 1000 adults, then contact them by telephone and ask them a survey question.

Question 11

Which of the following best describes a cluster sampling method?

Accepted Answer

The population is divided into groups, and all members of one or more randomly selected groups are included in the sample.

Question 12

A researcher wants to estimate the average commute time for workers in a large city. She randomly selects 10 companies and surveys all employees at those companies. What type of sampling is this?

Accepted Answer

Cluster sampling

Question 13

Which of the following is a potential source of bias in a survey about illegal drug use among high school students?

Accepted Answer

Some students may not answer honestly due to fear of consequences.

Question 14

A researcher divides a population into males and females, then randomly selects 50 from each group. What type of sampling is this?

Accepted Answer

Stratified sampling

Question 15

Which of the following is NOT a characteristic of a simple random sample?

Accepted Answer

The sample is chosen by dividing the population into groups and selecting all members of one group.

Question 16

A researcher wants to study the effect of a new teaching method on student performance. She randomly assigns students to two groups: one uses the new method, the other uses the traditional method. What type of study is this?

Accepted Answer

Experimental study

Question 17

Which of the following best describes a parameter?

Accepted Answer

A numerical summary of a population.

Question 18

A researcher wants to estimate the proportion of students at a university who own a car. She surveys 200 randomly selected students. What is the sample in this study?

Accepted Answer

The 200 students who were surveyed

Question 19

Which of the following is an example of systematic sampling?

Accepted Answer

Selecting every 10th person from a list of all employees.

Question 20

A researcher wants to study the average income of households in a city. She divides the city into neighborhoods and randomly selects several neighborhoods, then surveys all households in those neighborhoods. What type of sampling is this?

Accepted Answer

Cluster sampling

Sampling Methods and Statistical Studies: Key Concepts and Applications

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